Conventionally, an optical-sensor-equipped display apparatus has been proposed that is provided with photodetecting elements such as photodiodes in its pixels and thereby is capable of detecting a brightness of external light and capturing an image of an object approaching its display panel. Such an optical-sensor-equipped display apparatus is supposed to be used as a display apparatus for two-way communication, or a display apparatus having a touch panel function.
In the case of a conventional optical-sensor-equipped display apparatus, when known composing elements such as signal lines and scanning lines, TFTs (thin film transistors), and pixel electrodes are formed through semiconductor processing, photodiodes and the like are formed on an active matrix substrate through the same processing (see JP 2006-3857 A, and “A Touch Panel Function Integrated LCD Including LTPS A/D Converter”, T. Nakamura et al., SID 05 DIGEST, pp. 1054-1055, 2005).
Further, a display apparatus obtained by modifying the above-described optical-sensor-equipped display apparatus by adding a touch sensor so as to obtain outputs of two sensor systems has been known (see, for example, JP 2006-133788 A, and “FPD International 2008 Forum A-32”, Latest Trends of Touch Panel Development, Korea, Samsung Electronics Co., Ltd., Nam Deog Kim et al., 2008).